The embattled Cabinet minister Andrew Mitchell gave a personal promise to Rwanda’s controversial leader that Britain would continue its multi-million-pound aid payments to the regime despite growing concerns within his department, according to documents obtained by The Independent.

The former International Development Secretary has been lambasted for his decision last month – hours before he moved jobs in the Cabinet reshuffle – to re-instate £16m of British aid to be spent by Paul Kagame’s government, which is facing accusations of fomenting conflict in neighbouring Congo.

Officials insisted there was nothing improper about the decision to remove the block put on the funds earlier this summer as part of an international aid freeze. Mr Mitchell, now David Cameron’s chief whip, has been accused of overruling advice from the Foreign Office and his own civil servants when he ordered the payment.

Internal documents from the Department for International Development, released under the Freedom of Information Act, underline the warmth of the relationship between Mr Mitchell and President Kagame, a one-time darling of the West following Rwanda’s 1994 genocide but now accused of increasing authoritarianism.

In a note made by civil servants of a telephone conversation between Mr Mitchell and Mr Kagame in February 2011, the Cabinet minister announced Britain was increasing its aid from £60m to £90m by 2015, much of it to be provided as “general budget support” paid direct to the Rwandan government.

The memo states: “SofS [Mr Mitchell]… recalled how they had recently discussed that Rwanda is an excellent development and delivers results… We will continue to provide a significant proportion of the UK’s aid as budget support. We will continue to provide high levels of general budget support (of £37m annually).”

Two months earlier he had flown out to Rwanda to see Mr Kagame for a “90-minute tête-à-tête followed by lunch” in which they had “friendly but robust” exchanges. That meeting followed Mr Kagame’s re-election amid accusations that he suppressed the opposition and gagged the media.

The meeting followed Mr Kagame’s re-election earlier that year amid accusations that he had suppressed the opposition and gagged the media.

It was this general budget support which Mr Mitchell unexpectedly re-instated last month, ordering £8m to be released immediately with a further £8m in December for education and food security. Labour has demanded Mr Mitchell publish the advice he received over the funding release.

During the telephone conversation, Mr Mitchell emphasised the personal links between the upper echelons of the Conservative Party and the Rwandan regime, dating from the period in opposition during which senior Tories intent on detoxifying their image visited the country to carry out aid work.

The memo continued: “Secretary of State said this reflected the UK’s long-term support to Rwanda (including from the PM, who had visited as leader of the Opposition in 2006). Pres Kagame was very grateful.”

The internal DfID memos underline the growing qualms within the ministry about the “political risk” in Rwanda with Mr Mitchell’s ministerial colleague, Stephen O’Brien, highlighting international concern about the human rights situation in the country.

In October last year, a senior DfID official warned that a joint monitoring scheme with Rwanda had stalled and suggested the use of general budget support would have to be re-visited.

Mr Mitchell’s successor, former Transport Secretary Justine Greening, is reportedly preparing to reverse Mr Mitchell’s decision, bringing Britain back into line with other countries – including the Netherlands, the US and Germany – who have continued to freeze aid following the findings of a UN report that Rwanda was supporting rebels from the M23 movement in the Democratic Republic of Congo. Rwanda has strongly denied the allegation.

The Cabinet Office said Mr Mitchell had not shied from raising difficult questions with Mr Kagame. In a statement, a spokesman said: “The former secretary of state had a candid relationship with the government of Rwanda and frequently delivered tough messages on issues of concern.”

A DFID spokesman said: “The Secretary of State will consider the issue of budget support to Rwanda carefully before our next decision in December.”

Minister’s messages: What was said

* Minutes of 90-minute “tête-à-tête followed by lunch” between Andrew Mitchell and President Kagame, December 2010: “The International Development Secretary raised a number of sensitive issues in candid terms, including the damage done to Rwanda’s reputation by the events around the August [presidential] elections, the need to open up political space and media freedom.”

* Telephone conversation between Andrew Mitchell and President Kagame, 24 February 2011: “SofS [Mr Mitchell]… recalled how they had recently discussed that Rwanda is an excellent development and delivers results… UK aid in Rwanda will grow from £60m this year to £90m in 2014-5. We will continue to provide a significant proportion of the UK’s aid as budget support. We will continue to provide high levels of general budget support (of £37m annually)… Pres Kagame was very grateful – this outcome showed the value of the partnership between Rwanda and the UK.